KTKohei Takei

Kohei Takei

*This is an algorithmically generated author record based on publicly available information.

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Kohei Takei has a total of 21 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Association between Immune Checkpoint Inhibitor Treatment Outcomes and Body Composition Factors in Metastatic Renal Cell Carcinoma Patients

    by Kohei Takei, Toshiki Kijima, Naoya Okubo, Ryo Kurashina, Hidetoshi Kokubun, Toshitaka Uematsu, Hironori Betsunoh, Masahiro Yashi, Takao Kamai

    Introduction: Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of metastatic renal cell carcinoma (mRCC); however, validating body composition-related biomarkers for their efficacy remains incomplete. We evaluated the association between body composition-related markers and the prognosis of patients with mRCC who received ICI-based first-line therapies. Patients and Methods: We retrospectively investigated 60 patients with mRCC who underwent ICI-based therapy as their first-line treatment between 2019 and 2023. Body composition variables, including skeletal muscle, subcutaneous fat, and visceral fat indices, were calculated using baseline computed tomography scans. Sarcopenia was defined according to sex-specific cut-off values of the skeletal mass index. The associations between body composition indices and objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) were evaluated. Results: Patients with sarcopenia had lower ORR and DCR than those without sarcopenia (33.3% vs. 61.1%, p = 0.0436 and 52.4% vs. 94.4%, p = 0.0024, respectively). Patients with sarcopenia had a significantly shorter median PFS (14 months vs. not reached, p = 0.0020) and OS (21 months vs. not reached, p = 0.0023) than patients without sarcopenia did. Sarcopenia was a significant predictor of PFS (hazard ratio [HR], 4.31; 95% confidence interval [CI], 1.65–14.8; p = 0.0018) and OS (HR, 5.44; 95% CI, 1.83–23.4; p = 0.0013) along with poor IMDC risk. No association was found between the subcutaneous, visceral, and total fat indices and the therapeutic effect of ICI-based therapy. Conclusions: Sarcopenia was associated with a lower response and shorter survival rates in patients with mRCC who received first-line ICI-based therapy.


  • Open Access

    Successful management of ureteral injury after gender-affirming laparoscopic hysterectomy: A case report

    by Gaku Nakamura, Akinori Nukui, Issei Suzuki, Kohei Takei, Toshiki Kijima, Takao Kamai

    A two-step process involving ureteral stenting and surgical repair is generally recommended to manage a delayed diagnosis of postoperative ureteral injury; however, retrograde stenting is often difficult. A 35-year-old female-to-male transgender person who underwent laparoscopic gender-affirming total hysterectomy with bilateral salpingo-oophorectomy developed right ureteral injury at 2 months postoperatively. Initially, the stenting guidewire could not pass through the stenotic tract and was diverted into the abdominal cavity. Using a 0.014-in. microguidewire and a 2-Fr microcatheter, both of which are designed for angiography, the ureteral stent was ultimately placed. The patient underwent surgical repair using the Boari flap technique. The double J catheter was removed at 1 month postoperatively, and postoperative retrograde pyelography revealed no urinary leakage or ureteral stricture. Immediate primary repair is desirable for intraoperative ureteral injuries. However, up to 70 % of ureteral injuries are diagnosed during the postoperative period. For a delayed diagnosis of ureteral injury, urinary diversion with ureteral stent, nephrostomy, or both, followed by delayed repair, is recommended to avoid the inflammatory phase. In this patient, ureteral stenting was difficult on the first attempt. Thin microguidewires designed for angiography could be useful in such difficult situation. A ureteral injury at the mid-ureter diagnosed at 2 months postoperatively was successfully managed using a two-step process involving ureteral stenting and surgical repair. A microguidewire and a microcatheter are useful for successful stenting in patients with late-diagnosed, severe ureteral strictures.


  • Open Access

    Performance characteristics of prostate-specific antigen density and biopsy core details to predict oncological outcome in patients with intermediate to high-risk prostate cancer underwent robot-assisted radical prostatectomy

    by Masahiro Yashi, Akinori Nukui, Yuumi Tokura, Kohei Takei, Issei Suzuki, Kazumasa Sakamoto, Hideo Yuki, Tsunehito Kambara, Hironori Betsunoh, Hideyuki Abe, et al.

    Many urologic surgeons refer to biopsy core details for decision making in cases of localized prostate cancer (PCa) to determine whether an extended resection and/or lymph node dissection should be performed. Furthermore, recent reports emphasize the predictive value of prostate-specific antigen density (PSAD) for further risk stratification, not only for low-risk PCa, but also for intermediate- and high-risk PCa. This study focused on these parameters and compared respective predictive impact on oncologic outcomes in Japanese PCa patients. Two-hundred and fifty patients with intermediate- and high-risk PCa according to the National Comprehensive Cancer Network (NCCN) classification, that underwent robot-assisted radical prostatectomy at a single institution, and with observation periods of longer than 6 months were enrolled. None of the patients received hormonal treatments including antiandrogens, luteinizing hormone-releasing hormone analogues, or 5-alpha reductase inhibitors preoperatively. PSAD and biopsy core details, including the percentage of positive cores and the maximum percentage of cancer extent in each positive core, were analyzed in association with unfavorable pathologic results of prostatectomy specimens, and further with biochemical recurrence. The cut-off values of potential predictive factors were set through receiver-operating characteristic curve analyses. In the entire cohort, a higher PSAD, the percentage of positive cores, and maximum percentage of cancer extent in each positive core were independently associated with advanced tumor stage ≥ pT3 and an increased index tumor volume > 0.718 ml. NCCN classification showed an association with a tumor stage ≥ pT3 and a Gleason score ≥8, and the attribution of biochemical recurrence was also sustained. In each NCCN risk group, these preoperative factors showed various associations with unfavorable pathological results. In the intermediate-risk group, the percentage of positive cores showed an independent predictive value for biochemical recurrence. In the high-risk group, PSAD showed an independent predictive value. PSAD and biopsy core details have different performance characteristics for the prediction of oncologic outcomes in each NCCN risk group. Despite the need for further confirmation of the results with a larger cohort and longer observation, these factors are important as preoperative predictors in addition to the NCCN classification for a urologic surgeon to choose a surgical strategy.